Game-changer for stem cell research

Three years ago, scientists developed a technique to reprogram adult human cells into stem cells, which could then be studied like embryonic stem cells. Hailed as one of the biggest scientific breakthroughs of the decade, it gave researchers access to embryo-like cells while avoiding the sticky ethical issues that accompany the use of cells from human embryos. However, the method for making iPS cells is not only highly inefficient, but poses a risk for cancer.